Then & Now

Bennington, January 5th

 In the last few days the Allegheny Eastern has experienced major upheaval. The photo to the left was taken on January 5th. This is the east side of Tunnel Hill, near Bennington. The New Portage branch and westbound mains are at table top level. The eastbound mains are elevated 1 1/2" and the New Portage bridge carries them over the branch. The tunnels are in place. The twin bores are sitting on the table top and the New Portage tunnel has been raised to match the elevation of those tracks. All in all it's pretty flat for the top of The Hill.

Bennington, February 6th

In contrast, this photo of the same area was taken today. All of the mains have been elevated. The westbound mains are now sitting 1 1/2" higher at the tunnels. The eastbound mains are still 1 1/2" at the bridge, but now run uphill to the 3" elevation at the apex of Horseshoe Curve. All the track has been realigned further "south" leaving a large area "north" of the New Portage bridge. The spline roadbed seen here has been recycled for the most part, only the section running east to Horseshoe is new. The splines are not only reusable, they are also still flexible and can be bent to a new radius when needed.

Horseshoe, January 5th

To the right is a photo of Horseshoe Curve as it looked on January 5th. Once again everything is laying directly on the table top, elevation 0" (more or less). The curve is pretty much centered on the aisle. The eastbound mains have dropped back to 0" after climbing to 1 1/2" at New Portage. The mainline from here all the way around to Antis (behind the glue bottles) is dead flat. The only thing on the entire layout that breaks up that flatness is the eastbound grade over the New Portage bridge.

You can see that there are not many opportunities for scenery in what is supposed to be mountainous territory.

Horseshoe, February 6th

This is no longer true. The photo on the right was also taken today and shows the elevated right of way running through Horseshoe Curve.

Styrosplines, Part 2

Because of design constraints on the Allegheny Eastern I did not use the open frame benchwork suggested by many other modelers. The number 1 design parameter was set by my wife. There had to be plenty of storage space under the layout. This required a flat frame. I set the height to about 51” based on the height of three Rubbermaid containers stacked atop each other. I then built several frames with legs (and wheels) using 2” x 4” pine studs fastened with drywall screws. The subtop is a grid of 2” x 4” studs spaced about a foot apart. I then covered the grid with ¼” underlayment and ½” extruded foam sheathing. The end result was a HUGE table top that fills most of our two car garage.

Unfortunately such a flat table top can cause some distinct issues for a model railroad. There no real way to model scenery below the track without cutting into the 2”x 4” frame. To get scenery below track level, you need some way to raise the track. After experimenting with more than a few ideas, I decided to use spline roadbed. Typically spline roadbed is a lot of carpentry work. I accidently discovered the technique I’m using and thought other modelers might be able to use it. I create my roadbed from cheap extruded styrofoam sheathing sold in many home remodeling stores.

Tools

This picture shows all of the tools required to make spline roadbed out of extruded styrofoam panels. I use a single edge razor blade like the kind used in utility knives. They can be found everywhere. The other tool may be a little harder to come by. It's an 8 foot long aluminum straight edge I purchased years ago for home remodeling. An 8 foot drywall square would work just as well. I'm making my splines 8 feet long, but you can also work with shorter lengths. The trick is figuring out the height at each end of the spline based on the grade you are creating. To create the grade between SLOPE and Horseshoe I’m going for a rise of 3” over 20 feet. That’s about a 1.25% climb. According to my math that works out to 3 pieces of Styrofoam for each spline.

One (1) 96” long rising from 0” to 1.25”

One (1) 96” long rising from 1.25” to 2.5”

One (1) 48” long  rising from 2.5” to 3”

Marking the Cuts

Using ½ ” material I need two of these spline “sets” for each track on the four track main, eight in all. Keep in mind that this is only for the climb out of Altoona, about a third of the 70 foot mainline. Another set will be required to complete the elevation of the mainline through Gallitzin.

I’m starting in the middle creating the spline that runs from 1.25” to 2.5”. I measure the splines in pairs. The dimensions are transposed at each end allowing me to make two splines from a rectangular chunk of the styrofoam.  I then cut along the straightedge with the razorblade. Rather than try to cut in one pass, I make several shallow cuts. I then snap the pieces apart at the cuts.

Splines

 The result is two splines of “almost” the same dimensions as shown here. I say Almost because my current cutting technique doesn’t create two identical pieces. They are close enough however, that only a slight amount of trimming is necessary to make them match.

Pulling Up the Track

For various reasons I built the Allegheny Eastern in stages, usually marked by a visit from my grandchildren. Each phase is complete enough that trains can be run over the entire mainline. Once the kids are gone, the next phase of construction begins. In this case the “next phase” is elevating and realigning the mainline between SLOPE tower in Altoona and Gallitzin Road in Gallitzin. 

Before I can install the new roadbed I have to remove the old. The track is held down using track nails which can be quickly removed. The track can then be laid off to the side. The “roadbed”, which is really just ballast strip glued to the foam table top, is pulled up next. Tacky glue was used to fasten the ballast strip. It holds firmly in place until you want to remove it. Pulling it up is just a matter of carefully lifting the strip so it doesn't get caught and tear. It comes up easy and can be reused on the new roadbed. Tacky glue is pretty amazing stuff!

Applying Tacky Glue

Once the track is pulled up and set to the side I start installing the splines, in this case the first piece of the middle set. I apply tacky glue to the bottom of the spline and then put it in place on the layout. I then move the spline back and forth a bit to smear the glue between the spline and the foam table top.

I lay the entire section in one operation and then adjust accordingly, preferring to use a freehand method of laying the curves. I try to allow the natural flex of the spline to dictate the flow of the curve. I can form it into tighter curves if needed. Since, however, all the curves on the layout are broad by N scale standards this is usually not necessary.

Drywall Screw "Clamps"

To keep the spline in place while the glue sets I was using all kinds of weights and other paraphanalia until I hit upon the idea of pushing 3” drywall screws into the foam table top. Like the track nails I use, they hold firmly in the foam. Strongly enough in fact to act as clamps while I lay up the next section or let the glue dry.

The tacky glue creates a strong flexible bond that can withstand to movement of N scale equipment. I'm convinced that with N scale at least, heavy construction materials are not required. I use 2x4s for the bench work out of cost concerns rather than strength. I'm not building kitchen cabinets here and cannot justify the extra expense.

McGarvey's Curve

Looking down on McGarvey’s Curve you can see the kind of “sweeper”created by allowing the spline to form a natural curve. Can’t tell you the specific radius, I lay these out by eye rather than dimensions. I think I end up with track that appears to flow like the prototype does. Because the radius is not set the splines tend to bend tighter towards the apex or center. The resulting curves appear to widen at each end, giving the impression of an easement. When large steam engines were common, railway engineers had to include easements as a way to funnel those long rigid wheel bases into curves.

Gluing the Second Spline

The second section is installed by applying tacky glue to one side and the bottom. The new spline follows the first in direction and curvature. The two are glued to each other and the table top, creating a strong base for the track. You can also see that now there will be room below track level for quite a bit of scenery. 1" is about 13.5 feet in N scale, so this area will be almost 33.5 feet above the table top. At Horseshoe Curve the elevation will be about 47 feet above Altoona Reservoir. Granted this may not be the kind of construction you might use in modeling the Western Pacific, but it works well enough for Pennsylvania. Of course you could always use taller splines, but on the Allegheny Eastern that would require elevating all of the track. Hmmm...I wonder...Better not go there

Second Spline in Position

With the second spline in place the “almost identical” dimensions are quite obvious. That straightedge I use isn't always straight (its actually two four foot sections that slide into each other) and this is the result. Not to worry, however, as this can be easily "adjusted". It took me a while to work out the technique, but it is clean and neat...More on that a little further on.

That's another advantage to some of the materials and techniques I use. I don't need power saws or sanders to create most of this stuff. Did you know you can cut 5mm plywood underlayment with a utility knife?

Second Spline, McGarvey's Curve

 Looking back towards McGarvey’s Curve you can see that the second section lies directly alongside the first and creates a smooth flowing curve. I have built the corner out to support the new right of way. It uses very little of the aisle space at this point while creating gobs of space on the layout. Eventually the entire "fascia" will be extended about an 1 ½” into the aisles. This will get some of the trackwork away from the edge and little fingers that sometimes get too close to these tiny models.

In this view you can see how much space now exists between the new right of way and the trolley line in the background.

Trimming

Once the second spline is in place I use the razor blade to trim the two sections to the same height. You can see that I lay the blade on top of the spline and slice away the excess. Previously I had done this with a scraping or filing method and was not pleased with the end result. The top of the roadbed got pretty beat up and although the ballast strip covered it up I wanted something a lot smoother. Slicing with the razor leaves a much cleaner and even surface.

Ballast Strip Installed Track 1

I wouldn’t normally lay the ballast strip at this stage, but I wanted to show how this works. Two sections of ½” thick spline are exactly the same width as the Woodland Scenics ballast strip I use. Even better, when all four tracks are in place they will be spaced on 15' centers, the Pennsy (and Allegheny Eastern) standard. I know other modelers allow more room but on the All East the curves are broad enough to allow prototype spacing. There is very little overhang on the passenger cars and no sideswipes have occurred (as yet) even with the 80 footers.

Waiting for the Glue to Set

With two sections in place it’s time to let the glue set. While the drywall screws keep the spline in place horizontally, weight is still needed to hold the spline to the table top. I use coffee cans full of bolts as weights. I usually allow about twenty four hours for the glue to set before continuing to the next section.

The next section can either be the other pieces in the set, thus completing 20 feet of roadbed for that one track, or by adding adjacent sections for the other three tracks. I prefer to complete one track at a time. It’s easier to realign one track with its roadbed than four. I may not mind redoing a thing, but I'd rather not redo that much.

In the next installment we may see Track 1 extended all the way trough Gallitzin. Reusing the  splines from the New Portage grade has given that area a head start.

"Styrospline"

Allegheny Eastern February 4th, 2012

More doodling led to more ideas on what might be done. The latest update of the track plan shows that the general layout of the mainline remains the same except for the realignment between MP10 and MP25. Horseshoe Curve has been relocated about 10" "north" and the approach to The Curve straightened out to allow more room in Altoona.

The eastbound main between MP45 and MP30 has also been realigned further "south" bring the tunnel bores closer together. This leaves enough open space in Gallitzin for a Hollidaysburg staging yard on the New Portage branch. There's some reworking of the trackage for the Altoona Northern and Altoona & Logan Valley. On the A&LV I made the return loop much larger and placed the carbarn and industry tracks inside.

"Styrospline"

So much for the track plan. Incorporating these changes into the actual layout seems like a bit of work, but again the construction methods used allow for some pretty big changes. One of the techniques I'm using worked out better than I imagined. The styrofoam spline used to create the New Portage grade proved to be a huge asset. At right is a picture of the spline where each section the roadbed was essentially a 1/2" square. The four parts are glued together with tacky glue and are almost inseparable. Not only is the spline super easy to create, the only tools required are a razor blade and straightedge, it's cheap. A 4' x 8' sheet of  1/2" thick foam is less than $15...You can get a lot of spline out of that sheet.

"Old" Roadbed

One advantage I hadn't foreseen was the road bed can  be re-used. It remains flexible! I found that I could reuse the section between MP30 and MP35. In the photo on the left the roadbed is still in it's original location. The New Portage bridges have been moved to their new location towards the center of the picture and the track has been moved to approximate the new alignment. The roadbed between the bridges old location and the camera will need to be removed. I pulled it loose from the table top and realizing how flexible it was just swung it into position along the new alignment.

Flexible Spline

To my surprise it went into place creating a broad curve. If I were going to reuse it in this location all I would need to do is glue it back down and relay the track. Instead I now know it can used elsewhere on the layout, another component that's recyclable. Since I tend to use construction materials over and over this fits in well with the other design and construction methods developed so far. Kind of an "instant" 1.5% grade for two tracks. Makes me wonder if the spline could be made up ahead of time and then "flexed" into alignment. The flex of the material would create natural broad curves. I'm pretty sure the spline would have to be laid down two tracks at a time. A spline for all four tracks would be four inches across and not quite as flexible.

Revised New Portage Area

It didn't take long to layout the modifications to the Tunnel Hill / New Portage section. You can see that the New Portage bore is much closer to the Twin Tunnels and is a better representation of the area being modeled. There is now a great deal of space available for the New Portage branch to actually travel somewhere. Current plans call for a kind of "staging" yard, but other opportunities may develop. The westbound tracks will also be elevated, but only about half the height of the eastbound. The eastbound roadbed to the right of the bridge will run uphill from the 1.5" elevation at the bridge to the 3" maximum at Horseshoe. The westbound main will drop from 3" at Horseshoe to about 1" at the twin tunnels.

McGarveys

As for the other areas being revised the photo on the right shows the new alignment at McGarveys Curve at the lower right hand corner. The faint blank line running between the mainline and the Altoona and Logan Valley tracks is the edge of the old alignment. There is now almost a foot of space available. There needs to be a mountain side in this area and there is now enough room to model one. The benchwork is being extended in this corner with a "triangle" of real estate to support the relocated tracks.

Kittanning, East of Horseshoe

The situation is the same in the opposite direction toward Horseshoe Curve. This shot of the Kittanning area show that the mainline has been moved aside. The short train is on the Altoona Northern interchange track in Juniata. The two areas are now separated horizontally by about 12" and vertically by almost 3". Just like at McGarvey's Curve, there is now enough room for a mountain side. This will be the site of Baker's Run and the Kittanning Run Railroad will connect here.

Burgoon Run, West of Horseshoe

The realignment on the west side of Horseshoe looking east from McCanns. The mainline now sits about 6" further "north". The tracks of the Glenwhite Coal & Lumber Co now turn off up Burgoon Run towards Gallitzin. The elevation at the turnout will be about 2.25" descneding towards the tunnels. The large vacant area without foam will support the Gallitzin sidings and the GC&L connection to the Altoona Northern and A&LV as shown in the updated plan. This is also the location of the "access hatch" to maintain the westbound tracks in Gallitzin.


The new splines will start going in this week. I hope to show some step by step construction photos of the splines being made and installed. Once they are in place the ballast strip can be glued back down and track relaid. For the first time since it's inception years ago, the Allegeheny Eastern may even be ready for real scenery.